INFO: task kworker/u4:3:840 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:21352 pid: 840 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_cat_write_inode+0x1e3/0x820 fs/hfsplus/inode.c:588 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715 writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x455/0xb90 fs/fs-writeback.c:2116 wb_check_background_flush fs/fs-writeback.c:2182 [inline] wb_do_writeback fs/fs-writeback.c:2270 [inline] wb_workfn+0xb47/0xe60 fs/fs-writeback.c:2298 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task kworker/0:5:4217 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:5 state:D stack:25856 pid: 4217 ppid: 2 flags:0x00004000 Workqueue: events_long delayed_sync_fs Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223 delayed_sync_fs+0x94/0xe0 fs/hfsplus/super.c:271 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:3/840: #0: ffff888141b88138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000394fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff888023b440e0 (&type->s_umount_key#51){.+.+}-{3:3} , at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff88807d95c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 2 locks held by getty/3945: #0: ffff88814d431098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 3 locks held by kworker/0:5/4217: #0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002dffd00 ((work_completion)(&(&sbi->sync_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88814cfba998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223 9 locks held by syz-executor.0/4592: 1 lock held by udevd/4888: 4 locks held by syz-executor.0/7651: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4592 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65 Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 RSP: 0018:ffffc90002eceff8 EFLAGS: 00000202 RAX: 00000000ffff0a00 RBX: ffff0a0000000509 RCX: 0000000000000000 RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffffc90002ecf098 RBP: ffffc90002ecf120 R08: dffffc0000000000 R09: ffffc90002ecf080 R10: fffff520005d9e13 R11: 1ffff920005d9e10 R12: ffff0a0000000509 R13: 00000000000000ed R14: ffffc90002ecf401 R15: ffff0a0000000509 FS: 00007fe1769996c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f54e2713c00 CR3: 00000000249f6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: number+0x277/0xf70 lib/vsprintf.c:457 vsnprintf+0x10fe/0x1a00 lib/vsprintf.c:2877 sprintf+0xd6/0x120 lib/vsprintf.c:3013 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x152/0x300 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] console_unlock+0x7f5/0x1200 kernel/printk/printk.c:2725 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:62 [inline] hfsplus_bnode_dump+0x30b/0x430 fs/hfsplus/bnode.c:369 hfsplus_brec_remove+0x476/0x540 fs/hfsplus/brec.c:229 __hfsplus_delete_attr+0x1d1/0x360 fs/hfsplus/attributes.c:299 hfsplus_delete_all_attrs+0x240/0x3a0 fs/hfsplus/attributes.c:378 hfsplus_delete_cat+0x94a/0xd20 fs/hfsplus/catalog.c:425 hfsplus_unlink+0x33c/0x760 fs/hfsplus/dir.c:385 vfs_unlink+0x385/0x600 fs/namei.c:4288 do_unlinkat+0x382/0x6f0 fs/namei.c:4356 __do_sys_unlink fs/namei.c:4404 [inline] __se_sys_unlink fs/namei.c:4402 [inline] __x64_sys_unlink+0x45/0x50 fs/namei.c:4402 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe177617b29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe1769990c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 00007fe177736f80 RCX: 00007fe177617b29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000 RBP: 00007fe17766347a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe177736f80 R15: 00007ffeac6723e8